To my knolage there are two companies tuning Grand Am's.
Digital Horse Power (DHP for short) and HP Tuner.
... Oh, i see you already have a DHP chip. Have you considered upgrading it to the "DHP PowrTuner"?
http://65.109.52.43/PowrTuner.htm
When I had a DHP chip in my car I left tuning it to the pro's.